This research outlines a series of studies to characterize virus- host cell interactions in specific terms for the purpose of identifying those factors giving rise to resistance and/or susceptibility in economically important lepidopterous larvae. The long-range goals of these studies are for purposes related to biological control, and to explore the systems described herein for providing insight to the specificity of pathogen-host relationships in invertebrates. The experimental design emphasizes the use of biochemical or techniques of molecular biology to study the virus-host interactions to elaborate upon and clarify the fate of infectious virus and virus components in the organism as compared to studies in tissue culture systems. Such studies hopefully will provide or allow insight and understanding of the controlling factors involved in the specificity of transmission and infection in insects such that potentially more effective systems may be effected and/or evaluated for biological control.